Electromagnetic drill unit



March 23, 1954 E W, BUCK ELECTROMAGNETIC DRILL UNIT 3 Sheets-Sheet l Filed May 10, 1952 J 9 3 2 0 J Du 2 4. .J l H. 3 .Q Z J n. .f duuunnn J 4. wgf PESCE d. wwmj-1- diw 0 m h u u n n 2 a3 m 2 M -rkwurmnwwwwwurw.H WHMW IIII -..WI 1.1M--.

mvENTon .EUGENE W BUCK ELECTROMAGNETIC DRILL UNIT Filed May 10, 1952 5 Sheets-Sheet 2 60 lll-: :lg/J kun- 4 INVENTOR EUGENE' W BUCK BY d4/LJ VM: '2

ATTORJVI'YJ MalCh 23, 1954 E. W BUCK ELECTROMAGNETIC DRILL UNIT 3 Sheets-Sheet 5 Filed May l0, 1952 INVENTOR .EUGEJVE W .BIGKY .ATTORNEYS Patented Mar. 23, 1954 ELECTROMAGNETIC DRILL UNIT Eiweiv Wf Blink, Campbell, Calif., essignor of ono-third to Antonio Cano, Santa Clara, Calif.

4 Claims.

The Vpresent: invention is directed to a. portable. electro-magnetically sunporteddrill unit. and particular'represents modifications `of the etruc ture shown in my depending application. Serial No. 254,993, filed November 6, 195i. on Portable Magnetic Base Drill.

The principalfobject ofi the present invention is to provide an electro-magnetic drill unit which is off simiiliiiedl but sturdy'and dependable construction. andofcompact sssembly;;the unit including a tubular main' post which houses the rectifier. thus eileetively shielding" the come against damage during normal use of seid unit.

Anotherl importent object of the instant lovention is to provide an electro-magnetic drill unit which is rigidly magnetically secured to a metal work-piece and thus very stable Vwhen in une: the invention contemplating the employment of one or more electro-magnetic `feet disposed in symmetrical arrangement relativo both to the drill and to a rear stabilizing'leg-whlch the device includes.

A further object of this invention is to provide an electro-magnetic drill: unit'fwhioh `permite of its magnetic attachmentfto a flat metal'work piece in a position for convenient drilling close to an edge of the work-piece or in a corner thereof.

.An` additional object of1 the Yinvention isi-to provide. as anafttachment. a device which permits the drill unit to be easily converted for use, in clamping engagement, on a round shaft or pipe.

It is also en object of the inventionto provide an electro-magnetic drill unit which is Vtlesisl'ied for ease and economy oftmaiiufeoture;V the unit being especially adapted. but not limited, for use with an initially separatelportable.orfhendgftype electric drill.

Still another object of the invention is to pro vide e practical and reliable i electro-magnetic drill unit. and one which willwho exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative-arrangement of Darts as will fully appear by e. perusal of the following speciiication and claims.

In the drawings;

Fig. 1 is a side elevation of the electro-mamut drill unit as in use with a single electro-magnetic foot; the view being broken ewefvin` part to show certain details.

Fig. 2 is a sectional plan view teken` through the mein post directly .above the base plate; the view showing such plate asl arranged with duel electro-magnetic feet.

Fig. 3 is a. fragmentary side elevation of the same.

Fig. 4 le a fragmentary elevation showing the Vtached from thc remainder of the drill unit.

Fig. 7 is a, cross section on line 1.-'1 oi Fig. 1.

Fig. 3 is a diagram oi' the circuit.

Referring now more particularly to the characters of reference on the drawings, and at preeent to Figs. l. '7 and 8, the electro-magnetic drill unit comprises an upstandns. tubular post l fitted, et its lower ond. with an enlarged circuler base plete 2 which is disposed substantially hori zontally.

Such base plate 2 is secured in matching roletion on top of an electro'megnetic foot. indicated generally at 3.

The electro-magnetic foot 3 comprises e circular body 4 of iron; which body is formed intornelly with en annuler channel 5 which houses a ring-like electro-magnetic coil B. The coil 5 is maintained in the channel 6 by means of e. bottom ring l Whose displacement is normally prevented by set screws 8. The base plate 2 is ailixed to the top of the body 4 by cap screws 9.

A bracket In is fixed to, and projects ree?- werdly from, the upstanding tubular poet I et the book of the letter; such bracket In being of relatively short extent radially of said post.

At its outer end the bracket in is formed with a vertical-axle boss Il, and the upper end of a. rear vstoliilizillg leg I2 is adjustebly threaded through such boss from below, The rear leg I2 is adjusted in its downward projection to hear on the metallic work-piece I3 in a manner so that the electro-magnetic foot 3 may rest flush on said Worknpiece.

A locking nut I4, threaded on the upper end of the leg I2. normally bears against the boss Il to prevent such leg from turning out of ad installent.

At the upper ,front portion thereoi' the post I is fixed in connection with a vertical guidewey l5, which guidewar extends from e point inter! mediate the ends of the post l upwardly to a top termination some distance tbereabove.

The guideway I5 includes eide grooves I5 fecing eeen other. and a slide I1 runs vertically in the suideway I5. being carried et opposite edges in the grooves I6. Friction strips la are disposed inthe grooves Il` and prevent too free motion or said slide I1; one of said friction strips IB being subject to adjustment by one or more adjustment screws I9.

The slide I1 is adapted to be manually run upwardly or downwardly as follows:

Such slide I1 is tted, on the inner face thereof and centrally of its side edges, with a vertical rack 25, and a pinion 2I disposed in a pinion housing 22 runs in mesh with said rack. The pinion housing 22 is disposed above the upper end of the post I, and the pinion 2I is carried on a cross shaft 23 which extends horizontally from side to side of said housing. Additionally, the housing 22 encloses a coil-type return spring 24 connected with said cross shaft 23.

At one end the cross shaft 23 projects out of the housing 22, and is there fitted with a spidertype handle 25.

n the front side thereof. and adjacent the top, the slide I1 carries an attachment plate 26 secured to said slide by screws 21; there being an attachment arm 28 which projects forwardly from the plate 26 for matching engagement with the handle 29 of a vertically disposed, portable electric drill 30. The arm 28 is attached to the handle 25 by a U-clamp 3I.

Additional connection is provided between the drill 30 and the slide I1 by means of a screw plug 32 threaded into the drill body, and attached to the slide by a screw 33 adjacent the lower end of said slide.

As so mounted, the drill 30 projects directly downwardly, with the drill chuck 34 above the Work-piece I3, but suiilciently close for a twist drill 35 carried by said chuck to run downward into such work-piece.

The coil of the electro-magnetic foot 3 is adapted to be D. C. energized, and to this end a cylindrical rectifier 35 of full-wave bridge type is disposed in the post I in protective relation, being secured therein by suitable means such as a set screw 31.

The circuit, which includes the coil 5 and rectier 35 (see Fig. 8 in conjunction with Fig. l), comprises a main A. C. supply circuit 38 in the form of a cord which leads into the post I tc connection with the rectifier 36; there being a switch 39 in one lead of said circuit, and which switch is mounted on the side of the post I adjacent the lower end thereof.

The rectiiier output circuit 40, in the form of a cord, leads out of the post I and thence passes downwardly through the base plate to connec tion, internally, with the coil 6 of the foot 3. In order to permit oi detachment of the foot 3, the

cord 40 has a plug and socket unit 4I interposed therein, and said cord 43 passes through an openended slot 42 in the base plate 2.

A signal light 43 is wired across the main circuit 33 beyond the switch 39, serving to indicate to the operator when the unit is electrically energized; said signal light being mounted on the front of the post I.

An electric socket 44 for plug-in of the cord (not shown) which energizes the drill 30 is mounted on one side of the bracket III in parallel connection with the main circuit 38,

With the above described electro-magnetic drill unit, the electric drill 30 is carried on a rigid, stable stand when the electro-magnetic foot 3 is adhered to the work-piece I3 with the rear leg I2 likewise bearing on the same. Thereafter, by the simple expedient of working the handle 25. the operator can run the drill 35 directly into the work. Also, by reason of the relative arrangement o! the parts-i. e. the twist drill ahead of the foot 3, and the leg I2 rearwardly of the latterthe device can be set so that the drill 35 may work near an edge or into a corner of said work-piece.

For heavy-duty work, or increased stability, it may be desirable to employ a pair of electromagnetic feet, and to this end the base plate 2 is formed. on opposite sides but adjacent the iront, with laterally outwardly projecting attachment lugs 45 which are forked. These lugs appear on the base plate 2, as shown in Fig. l, and in Figs. 2 and 3 such lugs are shown in use.

T'o employ two electro-magnetic feet, indicated at 45 and 41. the foot 3 is detached, and in lieu thereof the feet 45 and 41 are connected to the lugs 45 in adjacent but spaced side by side relation. The feet 45 and 41 include upstanding tongues 48 and 49 which are bolted into the corresponding lugs 45, as shown; such feet being of the same construction and electrical arrangement with respect to the coil as the foot 3. The feet 45 and 41 have electric supply cords 53 and 5I which lead upwardly; the cord 5I being adapted to connect with the plug and socket unit 4I on the post I, while the cord 50 has similar connection (not shown) on the opposite side of said post.

In the embodiment of Fig. 4 the post is indicated at 52, and at its lower end has pivotal connection, as at 53, with the base plate 54 secured to the electro-magnetic foot 55, as aforesaid. The purpose of the pivotal connection 53, which has a transverse horizontal axis, is to permit the foot to accommodate itself to any unevenness which may exist in the Work-piece 56.

In order to prevent the post 52 from tipping too far forwardly about the pivotal axis 53 when the foot 55 is deenergized, a stop screw 53 is threaded through a forwardly projecting boss 55 and extends downwardly to adjacent but short of the foot 55 ahead of said pivotal axis.

Under certain working conditions it may be desired to employ the device in connection with radial drilling of a round work-piece, such as a pipe or a shaft. To accomplish this I provide the attachment device shown in Figs. 5 and 6.

This device comprises a saddle block 6I adapted to seat on the round work-piece 52, the saddle block 5I being attached to the lower end of the post P of the device by securing said block to the base plate, here indicated at 53. In the present instance the base plate 33 is shown as having pivotal connection 64 with the post in the manner of Fig. 4, but a fixed connection, as in Fig. l, can be employed if desired. A chain 65 is anchored to one end of the saddle block 6I, as at 5B, and thence extends downwardly under the workpiece 52 and upwardly over a sprocket 51 nxed on a cross shaft 68 journaled in connection with, but spaced outwardly from the saddle block 5I.

After manual engagement of the chain 65 under the work-piece and'over the sprocket 51, said chain is tightened by rotation ofthe cross shaft 53 through the medium of a hand lever 53 thereon.

Intermediate the sprocket 51 and hand lever 63, the cross shaft 63 carries a ratchet wheel 10 with which a releasable holding pawl 1I coopcrates. The holding pawl 1I, working against the ratchet wheel 10, maintains the chain 55 taut about the work-piece 62.

With the above described attachment device the drill unit can be effectively set to drill radially into the work-piece 52.

From the foregoing description it will be readily seen that there has been produced such a device as will substantially fulfill the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described the invention the .following is claimed as new and useful, and upon which Letters Patent are desired.

1. A drill unit comprising an upstanding post, a support for an electric drill, means mounting the support on the post at the front for up and down motion, a pair of electro-magnetic feet disposed in transversely spaced relation symmetrically below the post, means securing the feet in connection with the lower end of the post, a rigid bracket projecting from the lower portion of the post at the rear, and a stabilizing leg extending downward from the outer end of the bracket.

2. A drill unit comprising an upstanding post, a support for an electric drill, means mounting the support on the post at the front for up and down motion, an electro-magneticfoot disposed below the post, a base plate between the lower end of the post and the foot and secured to the latter, a rigid bracket projecting from the lower portion of the post at the rear, a vertically adjustable stabilizing leg extending downward from the outer end of the bracket, and a pivot connecting the base plate and the lower end of the post; the axis of the pivot being disposed at right angles to a median line drawn between a drill and the leg.

3. A drill unit comprising an upstanding post, a support for an electric drill. means mounting the support on the post for up and down movement and so that the axis or a drill is spaced from the front side of the post a predetermined distance, an electromagnetic foot mounted in connection with the post directly below the same, a bracket projecting rearwardly from the post adjacent the lower end thereof, and a stabilizing leg depending from the bracket; the lower end of the leg, post and drill lying substantially in a common horizontal line.

4. A drill unit comprising an upstanding post, a support for an electric drill, means mounting the support on the post for up and down movement and so that the axis of a drill is spaced from the front side of the post a predetermined distance, an enlarged base plate on the lower end of the post for removable mounting on a magnetic foot, lugs projecting laterally from the base plate and post on opposite sides of the latter, and elements removably connected to and depending from the lugs for mounting connection with transversely spaced magnetic feet when the first named foot is dismounted from the base plate.

EUGENE W. BUCK.

References Cited in the iile of this patent UNITED STATES PATENTS Number Name Date 596,375 Murchie Dec. 28, 1897 676,043 Lincoln June 11, 1901 1,023,921 Brown Apr. 23, 1912 1,176,584 Madgett Mar. 21, 1916 1,184,829 Crist May 30, 1916 2,024,390 Roesch Dec. 17, 1935 FOREIGN PATENTS Number Country Date 369,374 France Jan. 10, 1907 691,267 France July 7, 1930 

